colour above the cheek-bones, with a reasonable,
thoughtful forehead, and a dash of absolute obstinacy
in her thin lips and prominent chin. Snow white
cuffs and collar, with a plain dark dress, cut with
almost Quaker-like simplicity, bespoke the primness
of her taste. An ebony cross hung over her flattened
chest. She sat very upright in her chair, listening
with raised eyebrows, and swinging her eye-glasses
backwards and forwards with a nervous gesture which
was peculiar to her.

Suddenly she gave a sharp, satisfied jerk of the
head, and began to pour out the coffee. From outside
there came the dull thudding sound of heavy feet upon
thick carpet. The door swung open, and the Professor
entered with a quick, nervous step. He nodded to his
sister, and seating himself at the other side of the
table, began to open the small pile of letters which
lay beside his plate.

Professor Ainslie Grey was at that time forty-
three years of age--nearly twelve years older than
his sister. His career had been a brilliant one. At
Edinburgh, at Cambridge, and at Vienna he had laid
the foundations of his great reputation, both in
physiology and in zoology.

His pamphlet, On the Mesoblastic Origin of
Excitomotor Nerve Roots, had won him his fellowship
of the Royal Society; and his researches, Upon